Electromagnetic response and optical properties of spherical CuSbS₂ nanoparticles

We study the electromagnetic response of individual spherical copper antimony disulfide (CuSbS₂) nanoparticles and layers embedded with them for solar applications and near infrared (NIR) sensors using computational methods. We first calculate the single particle scattering and absorption efficiencies using Lorenz-Mie theory. The absorption and the total scattering efficiencies broaden and shift to longer wavelengths with increasing particle radius from 1 to 100 nm. We further investigate the response of multiple nanoparticles embedded in a thin layer at a low volume fraction using a Monte Carlo method. Our results demonstrate that with increasing particle size and scattering NIR transmittance is strongly suppressed and absorption and reflectance enhanced. The high absorption coefficient and solar-compatible band gap of CuSbS₂ make it a good candidate for nanocrystalline solar cell and other NIR device applications.